Although most bulbs can be left in the ground in mild winter zones, many flowering bulbs, such as, gladiolus, alliums, oxalis and canna, cannot withstand harsh winter zones. After your bulbs have finished flowering, it is best to leave the foliage to ripen naturally. The foliage is what provides nutrients to the bulb for future growth. You will know that it has ripened completely when it turns yellow or brown and the slightest pull will detach it from the bulb in the ground.
To lift the bulbs, insert a spading fork straight down into the ground, clear of the plant and deep enough to carefully lift the bulb from the ground. Gently loosen and removal the soil around the bulb, pull off any dead leaves, roots and bulblets. Place the bulbs in a tray, preferably in a mesh tray, uncovered, and placed the tray in a cool area, allowing the bulbs to dry for about seven to 10 days.